The discovery of new materials with novel chemical and physical properties often leads to the development of new and useful technologies. Over forty years ago, for example, the preparation of single crystal semiconductors transformed the electronics industry. Currently, there is a tremendous amount of activity being carried out in the areas of catalysis, superconductivity, magnetic materials, phosphors, nonlinear optics and high strength materials. Unfortunately, even though the chemistry of extended solids has been extensively explored, few general principles have emerged that allow one to predict with certainty composition, structure and reaction pathways for the synthesis of such solid state compounds, compositions or structures. Moreover, it is difficult to predict a priori the physical properties a particular three-dimensional structure will possess.
Clearly, the preparation of new materials with novel chemical and physical properties is at best happenstance with our current level of understanding. Consequently, the discovery of new materials depends largely on the ability to synthesize and analyze new materials, compounds, compositions or structures. Given approximately 100 elements in the periodic table that can be used to make such compositions consisting of three, four, five, six or more elements, the universe of possible new compounds remains largely unexplored. As such, there exists a need in the art for a more efficient, economical and systematic approach for the synthesis of possibly new compounds, compositions or structures (e.g., materials) and for the screening of such materials for useful properties, particularly materials useful for heterogeneous catalysis.
Pirrung, et al., have developed a technique for generating arrays of peptides and other molecules using, for example, light-directed, spatially-addressable synthesis techniques (see, U.S. Pat. No. 5,143,854 and PCT Publication No. WO 90/15070, incorporated herein by reference for all purposes; see also, Geysen et al, J. Immun. Meth. 102:259-274 (1987), incorporated herein by reference for all purposes). In addition, Fodor, et al. have developed, among other things, a method of gathering fluorescence intensity data, various photosensitive protecting groups, masking techniques, and automated techniques for performing light-directed, spatially-addressable synthesis techniques (see, Fodor, et al., PCT Publication No. WO 92/10092, the teachings of which are incorporated herein by reference for all purposes). Schultz et al., in U.S. Pat. No. 5,985,356 entitled “Combinatorial Synthesis of Novel Materials” disclose methods for preparing and screening arrays of materials for combinatorial material science applications such as catalysis, and is incorporated herein by reference. See also, e.g., U.S. Pat. Nos. 5,288,514 and 5,424,186, incorporated by reference herein.
Solution-based methods, such as the sol-gel process, are widely used for the synthesis of inorganic materials. An example of one system for the formation of combinatorial libraries is disclosed in PCT Application Serial No. WO/17413, based on commonly owned U.S. patent application Ser. No. 09/156,827, now abandoned, entitled “Formation of Combinatorial Arrays of Materials using Solution-Based Methodologies”, hereby expressly incorporated by reference. See also, WO 98/15969, hereby incorporated by reference. Also, of potential interest to the present invention are U.S. Pat. No. 5,959,297 “Mass Spectrometers and Methods for Rapid Screening of Libraries of Different Materials”, U.S. Pat. No. 5,585,136, “Method for Producing Thick Ceramic Films by a Sol Gel Coating Process”, PCT Application Serial No. WO 00/51720, based on U.S. patent application, Ser. No. 60/122,704, now abandoned, entitled “Chemical Processing Microsystems, Diffusion-Mixed Microreactors and Methods for Preparing and Using Same”, and Choi et al., “Combinatorial Methods for the Synthesis of Aluminophosphate Molecular Sieves,” Angew. Chem. Int. Ed. 1999, 38, No. 19 (2891-2894), each of which are hereby incorporated by reference.
This invention provides methods for the synthesis of combinatorial libraries or arrays on or in suitable substrates by effectively utilizing a certain combination of steps. The invention can be used to make known materials or new materials. In addition, this invention provides a general route for the synthesis of arrays of transition metal and other oxides for screening for heterogeneous catalytic properties.